1. Field of the Invention
The present invention relates to a control device for a vehicle four-wheel drive device, and particularly to a control of a four-wheel drive device in which a friction clutch is provided between a rear-wheel differential gear and either of right and left rear wheels.
2. Description of Related Art
There has been known a four-wheel drive device based on an FF vehicle in which a torque of a drive source is transmitted to front wheels at the time of two-wheel drive running and the torque of the drive source is transmitted to the front wheels and rear wheels at the time of four-wheel drive running. Such a four-wheel drive device is provided with a friction clutch for adjusting a torque split to be transmitted to the front and rear wheels. In a four-wheel drive device described in Japanese Patent Application Publication No. 2010-260383 (JP 2010-260383 A), a multi-plate clutch mechanism 30 is provided between a rear-wheel differential gear 26 and a right rear wheel 82. When a torque of the multi-plate clutch mechanism 30 is adjusted, a torque split between front wheels and rear wheels is adjusted.